Cru Wear/ Z wear heat treat advice wanted

Huntsman Knife Co. LLC.

Huntsman Knife Co. LLC.

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I picked up a sheet of .207 CPM Cru-wear today from Aldo for use in a 5in utility type blade. The blades will be HT by Peters.

For those who have experience with this steel what is the optimal hardness for a smaller to midsized blade that will be see hard use? For knives this size I typically use 3V at 61-62 austenized high and tempered low for carbide formation.

Judging from the data sheet it looks like 62 is the sweet spot for this steel.

I'm very excited to see how Cru wear/ Zwear performs. From what I understand it is a PM version of Vascowear which had a great reputation while it was around. If it performs as well as I'm hoping it looks like it will replace 3V in smaller blades.
 
Any updates?

I see no one replied with help, but I figured you'd have gotten something done on this anyway.

Thanks
 
For HT, you can visit Alpha Knife Supply's site....LOTS of good Info there.

I can't speak to CPM Cruwear, but I CAN speak to VascoWear, and Rc 60-62
would be about right for that. Triple tempering IS best.

Edge retention/stability is quite good. Corrosion resistance is moderate.....and it's
a good bit tougher than a hand-held knife should need to be...
 
Thanks for the reply! That's reassuring since earlier today, I sent some z-wear (along with my first 4v) to Peter's Heat Treat, with a target of Rc 61. From what I've read, I'll like everything about z-wear except the fact that I haven't found it for sale as surface ground anywhere. Everywhere is either hot rolled or descaled, and I don't have a reliable surface grinding method, making it a PITA to get a clean finish.
 
The finish on the "as received" steel isn't that important..!....since the only
part of the grinding process that may remain is the ricasso.....and that's
pretty easily refinished.
 
It's good to hear that it shouldn't be a pain, but it is important to those without machine tools. With so little equipment (just a Grizzly 1x30), smoothing that descaled surface required lots of hand-sanding. I wish I had had some better method to smooth out the tang/ricasso, and if you have suggestions, I'd gladly hear them!
Of course, the plan was always to invest in a proper grinder, but the time and finances weren't quite right when I started this hobby. In a few weeks, I'll have a proper grinder, and I expect much better results in much less time.

Thanks again.
 
I didn't mean to imply that finishing CruWear/Z-wear would be easy....anything but.
I meant that the ricasso....since it's relatively small, will not be much of a chore.

How close to finished dimensions are the blades pre-HT..?
 
Due to Z-wear and 4V being hard to work with post-HT, I wanted very little hardened steel manipulation, so I finished them to the point that all I have to do is fit handle scales and sharpen. I sand the entire surface from the tip through the tang to at least 400 grit prior to HT. I wasn't sure how finished they should be, so I asked when I had Peter's Heat Treat on the phone anyway, and 400 grit was recommended.
 
You can't go wrong asking Brad, or taking his advice.
Maybe you'll show the finished pieces...
 
Certainly! It'll be a couple weeks to get them back from Brad and to put handle scales on, but I'll post my results.

Here's a pre-HT pic of the 12. Z-wear on the left and 6 CPM-4V on the right.
92DE1E35-2F3E-4547-9F1A-6429E856CAC6_zps8e8xdkhx.jpg


The z-wear is the first non-stainless steel I have tried. I am experimenting with grind angles and ergonomics, as well as making a replacement blade for a KaBar Warthog folder (it had a hideous 420 blade, so I'm replacing that crap blade).

The 4V blades are 5 groomsmen's gifts + a larger one for fun.

I asked Brad to HT them all to Rc 61. That will provide plenty of wear resistance while maintaining plenty of toughness on both the Z-wear and 4V.
 
So, I received by first batch of blades from Peters' Heat Treat, and to my surprise they were mostly purple!
582ABCA3-DFE4-4A19-9FD5-14AD27E12739_zpsmtgxct3y.jpg


When I started my finishing sanding, I couldn't help but notice, that sanding isn't any more difficult now than it was prior to heat treating...
BUT, every time I read about sanding/grinding hardened high-alloy steels, people are saying how terribly difficult it is to work with.

I can scratch un-heat treated z-wear pieces with the heat treated stuff, but not vice versa, so that checks out, but something still seems off. Is this odd, or am I missing something?

I don't get it why the Z-wear and CPM-4V, both @ RC 61, seem to sand easier than descaled/hot-rolled Z-wear and 4V.
Are the various alloying elements so obstinate as to make annealed sanding just as difficult as hardened sanding?

Thanks!
Attila
 
The coloration is just a reaction to whatever gases were present when the blades were hot.

As for being as easy to sand after HT as before...I don't know.....The photo shows where each piece was cleaned for Rc testing....

so I'm wondering if all the "skin" was actually off of the flats...? Do the flats seem to be easier to sand than the bevels...??
 
Russ Andrews said:
The coloration is just a reaction to whatever gases were present when the blades were hot.

As for being as easy to sand after HT as before...I don't know.....The photo shows where each piece was cleaned for Rc testing....

so I'm wondering if all the "skin" was actually off of the flats...? Do the flats seem to be easier to sand than the bevels...??
Click to expand...

I wasn't expecting that specific coloration, since vacuum furnaces are used by PHT.

I meant to add that, yes, I trust that Brad @ PHT did a great job and hit the RC 61 target, so don't misunderstand me as doubting his work...

The flats and bevels sand the same. I haven't sharpened any edges yet, so don't know how tough that will be.

By "skin" do you mean the purple scale? The purple layer comes off really easily, and subsequent sanding is unexpectedly easy. I guess, I should specify that I'm hand-sanding via Norton Blue-Bak silicon carbide paper during this stage.
 
If there is any skin, it would show as a very thin layer of decarburized steel between
the mill scale and the inner bar stock. The assumption that this may be present is why
it's best to sand the area to be RC tested.....as Peters has done.


If , as you have experienced, there is no difference between the sanding of the bevels and the flats,
then there would be another explanation for that.
 
Thanks!

I'm comparing clean steel surfaces. Maybe the relatively soft hot-rolled steel was just gumming up my abrasives, making sanding more difficult than sanding the hardened surface, which don't gum up the abrasive... That's purely speculation, as I have no science to back it up.

Regardless, I thought sanding post heat treat was gonna be a bear, but it's really not too bad.
 
There is the "ghost" of the little knife, above the bigger ones, in the ht'ed picture... I think it's not the best idea to quench in pairs...or worst.
 
All things are relative.......if you think your blades are easy to sand after HT....Go for it....let us know
how they perform...
 
Attila......there comes a time when we just have to go for it......DO it
and see what it's worth...
 
Russ Andrews said:
All things are relative.......if you think your blades are easy to sand after HT....Go for it....let us know
how they perform...
Click to expand...

I was unsure at first, since I've never had pre and post ht'd steels to compare, but I think I was expecting a more drastic difference.
I'm also very curious how they will perform.

Also, I didn't want/need to sand after heat treat. It's just not too difficult, so I'm cleaning up the surfaces of a couple that could use some closer attention.

Russ Andrews said:
Attila......there comes a time when we just have to go for it......DO it
and see what it's worth...
Click to expand...

Sorry, but I don't understand your meaning...

stezann said:
There is the "ghost" of the little knife, above the bigger ones, in the ht'ed picture... I think it's not the best idea to quench in pairs...or worst.
Click to expand...

I noticed that too, but I trust the professionals who have earned such a great reputation.
 
".....Also, I didn't want/need to sand after heat treat. It's just not too difficult, so I'm cleaning up the surfaces of a couple that could use some closer attention.
...."

If you want knives that look and cut good, you always need to sand after HT. Regardless of the HT method, there is a thin layer that needs to be removed. If you merely want a knife that cuts so-so, you could not do anything but put an edge on. If you want a knife that cuts good, you need to sand the bevels to make the edge thinner than it was at HT.
 
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